Quantification of 1,25-Dihydroxyvitamin D2 and D3 in Serum Using Liquid Chromatography-Tandem Mass Spectrometry
2.4 Internal Standards 1. 1α,25-Dihydroxyvitamin D3 (26,26,26,27,27,27-d6), Medical Isotopes, Pelham, NH. 2. 1α,25-Dihydroxyvitamin D3 (26,26,26,27,27,27-d6), Medical Isotopes, Pelham, NH. 3. Preparation of individual standard stocks (20 μg/mL):…